Photocatalysis is a green technology which converts abundantly available photonic energy into useful chemical energy. With a rapid rise of flow photoreactors in the last decade, the design and development of novel semiconductor photocatalysts is happening at a blistering rate. Currently, developed synthetic approaches have allowed the design of diverse modified/unmodified semiconductor materials exhibiting enhanced performances in heterogeneous photocatalysis. In this review, we have classified the so far reported highly efficient modified/unmodified semiconductor photocatalysts into four different categories based on the elemental composition, band gap engineering and charge carrier migration mechanism in composite photocatalysts. The recent synthetic developments are reported for each novel semiconductor photocatalyst within the four different categories, namely: pure semiconductors, solid solutions, type-II heterojunction nanocomposites and Z-scheme. The motivation behind the synthetic upgrading of modified/unmodified (pure) semiconductor photocatalysts along with their particular photochemical applications and photoreactor systems have been thoroughly reviewed.

/pdf/nanostructured-materials-for-photocatalysis-54b0fo6szc.pdf

Nanostructured materials for photocatalysis

Redox catalysis, including photocatalysis and (photo)electrocatalysis, may alleviate global warming and energy crises by removing excess CO2 from the atmosphere and converting it to value-added resources. Nano-to-atomic two-dimensional (2D) materials, clusters and single atoms are superior catalysts because of their engineerable ultrathin/small dimensions and large surface areas and have attracted worldwide research interest. Given the current gap between research and applications in CO2 reduction, our review systematically and constructively discusses nano-to-atomic surface strategies for catalysts reported to date. This work is expected to drive and benefit future research to rationally design surface strategies with multi-parameter synergistic impacts on the selectivity, activity and stability of next-generation CO2 reduction catalysts, thus opening new avenues for sustainable solutions to climate change, energy and environmental issues, and the potential industrial economy.

Surface strategies for catalytic CO2 reduction: from two-dimensional materials to nanoclusters to single atoms

Applications of Zeolites in Sustainable Chemistry

Enhanced photocatalytic H2-production activity of WO3/TiO2 step-scheme heterojunction by graphene modification

The presence of an excessive concentration of CO2 in the atmosphere needs to be curbed with suitable measures including the reduction of CO2 emissions at stationary point sources such as power plants through carbon capture technologies and subsequent conversion of the captured CO2 into non-polluting clean fuels/chemicals using photo and/or electrocatalytic pathways. Porous materials have attracted much attention for carbon capture and in the recent past; they have witnessed significant advancements in their design and implementation for CO2 capture and conversion. In this context, the emerging trends in major porous adsorbents such as MOFs, zeolites, POPs, porous carbons, and mesoporous materials for CO2 capture and conversion are discussed. Their surface texture and chemistry, and the influence of various other features on their efficiency, selectivity, and recyclability for CO2 capture and conversion are explained and compared thoroughly. The scientific and technical advances on the material structure versus CO2 capture and conversion provide deep insights into designing effective porous materials. The review concludes with a summary, which compiles the key challenges in the field, current trends and critical challenges in the development of porous materials, and future research directions combined with possible solutions for realising the deployment of porous materials in CO2 capture and conversion.

Emerging trends in porous materials for CO2 capture and conversion

Surface oxygen vacancy and defect engineering of WO3 for improved visible light photocatalytic performance

Monoclinic β-Ga2O3 nanosheets hold great potential applications in electronic, optical, and photocatalytic fields. In this study, two-dimensional β-Ga2O3 nanosheets were successfully fabricated thr...

Phase Transition of Two-Dimensional β-Ga2O3 Nanosheets from Ultrathin γ-Ga2O3 Nanosheets and Their Photocatalytic Hydrogen Evolution Activities.

Iron-containing HZSM-5 zeolite, which was shown as an efficient and stable photocatalyst for photocatalytic CO 2 reduction in our previous research, was chosen to prepare a Ti-HZSM-5 hybrid via sol-gel method. The characterizations by XRD, UV–vis DRS, Raman, and XPS demonstrate that Ti species highly dispersed as nanoclusters or mono-sites on the HZSM-5 zeolite surface. Compared with the common TiO 2 -HZSM-5 composite sample, the as-prepared Ti-HZSM-5 sample exhibits an enhanced activity for photocatalytic CO 2 reduction due to higher concentration of excited state electrons and faster electron transfer rate. The Ti-HZSM-5 sample with 0.99 wt% of Ti content is observed to have the highest rate for the photocatalytic CO 2 reduction. And the characterization results of photocurrent and ESR reveal that Ti species and Fe species work synergistically upon UV-light irradiation, therefore, we propose a possible reaction mechanism of CO 2 photoreduction on Ti-HZSM-5. This work highlights the promising prospect of hybridizing of the Fe-O species in zeolite with semiconductors for enhanced photocatalytic performance.

Na Tong

Papers

Surface oxygen vacancy and defect engineering of WO3 for improved visible light photocatalytic performance

Phase Transition of Two-Dimensional β-Ga2O3 Nanosheets from Ultrathin γ-Ga2O3 Nanosheets and Their Photocatalytic Hydrogen Evolution Activities.

Photocatalytic reduction of CO2 to CO over the Ti–Highly dispersed HZSM-5 zeolite containing Fe

PdSn/NiO/NaTaO3:La for photocatalytic ammonia synthesis by reduction of NO3− with formic acid in aqueous solution

HZSM-5 zeolites containing impurity iron species for the photocatalytic reduction of CO2 with H2O